Estimating changes in hydration status from changes in body mass: Considerations regarding metabolic water and glycogen storage

Roderick F G J King, Carlton Cooke, Sean Carroll, John O'Hara

    Research output: Contribution to journalArticlepeer-review

    29 Citations (Scopus)

    Abstract

    The potential for imprecision in the estimation of hydration status from changes in body mass has been outlined previously but the equations derived from these derivations appear inconsistent. Reconciliation of body mass loss in terms of sweat loss and effective body water loss is possible from specific equation sets provided that gains and losses of both body mass and water used in the derivation of sweat loss and to derive effective body water loss are in inclusive equation sets. This is obligatory so that mass and water changes as quantifiable determinants are consistent with both internal processes and external gains and losses. Thus, body mass loss, substrate oxidation, metabolic water, and all the terms used in simultaneous equation sets have to be reconciled not only as identical variables but mathematically balance exactly. The revised equation for effective body water loss given here is different from that originally proposed. Metabolic water is part of body mass loss corrected for substrate oxidation, fluid ingestion, and respiratory water to derive sweat loss and it may not be justified to also include water associated with glycogen as releasable bound water. Accordingly, our calculated effective body water loss is substantially a greater loss than originally supposed but clearly still less than the simple balance between mass loss and fluid ingested.

    Original languageEnglish
    Pages (from-to)1361-1363
    Number of pages3
    JournalJournal of Sports Sciences
    Volume26
    Issue number12
    DOIs
    Publication statusPublished - 13 Oct 2008

    Keywords

    • Glycogen
    • Hydration
    • Metabolic water
    • Osmolality
    • Water balance

    Fingerprint

    Dive into the research topics of 'Estimating changes in hydration status from changes in body mass: Considerations regarding metabolic water and glycogen storage'. Together they form a unique fingerprint.

    Cite this